Great questions. Unfortunately, there is usually no clear cut answer – and like many mental health disorders – it is likely caused by a combination of genetic, behavioral, and developmental factors. Anatomically speaking, Generalized Anxiety Disorder is most closely related to a disruption in the functional connectivity of the amygdala – the “emotional control center” of the brain – and how it processes feelings of fear and anxiety. Genetics also play a role in Generalized Anxiety Disorder. If you have a family member that also suffers from this disorder, your chances of suffering from it are increased, especially in the presence of a life stressor. Interestingly, long-term substance abuse also increases your chances of Generalized Anxiety Disorder, as the use of benzodiazepines can worsen your anxiety levels, as can excessive alcohol use. Tobacco use and caffeine are also both associated with increased levels of anxiety.
Some of these symptoms will most likely be present in a panic attack. The attacks can be so disabling that the person is unable to express to others what is happening to them. A doctor might also note various signs of panic: The person may appear to be very afraid or shaky or be hyperventilating (deep, rapid breathing that causes dizziness). Anxiety attacks that take place while sleeping, also called nocturnal panic attacks, occur less often than do panic attacks during the daytime, but affect a large percentage of people who suffer from daytime panic attacks. Individuals with nocturnal panic attacks tend to have more respiratory symptoms associated with panic and have more symptoms of depression and of other psychiatric disorders compared to people who do not have panic attacks at night. Nocturnal panic attacks tend to result in sufferers waking suddenly from sleep in a state of sudden fright or dread for no known reason. As opposed to people with sleep apnea and other sleep disorders, sufferers of nocturnal panic can have all the other symptoms of a panic attack. Although nocturnal panic attacks usually last no more than 10 minutes, it can take much longer for the person to fully recover from the episode.
Not everyone who worries a lot has an anxiety disorder. You may be anxious because of an overly demanding schedule, lack of exercise or sleep, pressure at home or work, or even from too much caffeine. The bottom line is that if your lifestyle is unhealthy and stressful, you’re more likely to feel anxious—whether or not you actually have an anxiety disorder. These tips can help to lower anxiety and manage symptoms of an anxiety disorder:
Fortunately, panic disorder is one of the most treatable of the anxiety disorders. Psychotherapy (sometimes called talk therapy), cognitive, or biofeedback therapy can all help alter a person's response to stimuli. Medications, such as antidepressants and beta-blockers, are another option. And certain lifestyle changes, such as limiting caffeine and sticking to a daily exercise plan, can decrease symptoms as well.
It is not unusual to experience only one or two symptoms at a time, such as vibrations in their legs, shortness of breath, or an intense wave of heat traveling up their bodies, which is not similar to hot flashes due to estrogen shortage. Some symptoms, such as vibrations in the legs, are sufficiently different from any normal sensation that they clearly indicate panic disorder. Other symptoms on the list can occur in people who may or may not have panic disorder. Panic disorder does not require four or more symptoms to all be present at the same time. Causeless panic and racing heartbeat are sufficient to indicate a panic attack.
There are a number of things people do to help cope with symptoms of anxiety disorders and make treatment more effective. Stress management techniques and meditation can be helpful. Support groups (in-person or online) can provide an opportunity to share experiences and coping strategies. Learning more about the specifics of a disorder and helping family and friends to understand better can also be helpful. Avoid caffeine, which can worsen symptoms, and check with your doctor about any medications.
Social Anxiety Disorder;Fear of social situations in which the person is exposed to unfamiliar people or to possible scrutiny by others. The individual fears that he or she will act in a way (or show anxiety symptoms) that will be embarrassing and humiliating, often times leading to avoidance of social situations and severe distress when participation in social situations can't be avoided. 
Medication does not cure anxiety disorders but can help relieve symptoms. Medication for anxiety is prescribed by doctors, such as a psychiatrist or primary care provider. Some states also allow psychologists who have received specialized training to prescribe psychiatric medications. The most common classes of medications used to combat anxiety disorders are anti-anxiety drugs (such as benzodiazepines), antidepressants, and beta-blockers.